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I’d love to see some hard numbers on the “sun cable”. At a high level it seems like the biggest pie in the sky bullshit.

by dav43 5y ago

rswail 5y ago
Well, they've got serious investors and serious money at stake. Why is the concept of long distance HVDC cables, large energy storage and reusing flat, sunny land to generate power seem to be "pie in the sky"?
- derriz 5y ago
  There were a bunch of projects like this (Xlinks in the UK, a big German one and a few others) based around the idea of generating solar electricity in northern Africa and selling into Europe via HVDC cables under the Mediterranean. What has killed these projects (although Xlinks are seemingly still releasing press releases on a regular basis) is the radical shift in the relative prices of the components. Laying HDVC cables under the sea was and remains expensive while the price of solar PV panels has dropped by nearly 90% in a decade. As a result, the economics don't really add up any more. The capacity factor for a typical solar PV panel in northern Africa is about double that of one sited in northern Europe. But this increased efficiency cannot be exploited. It's now significantly cheaper to simply install twice as many PV panels in the north of Germany than install half the number of panels in the Sahara AND build 1000km of transmission to get the electricity to the markets in northern Europe. There are other disadvantages also; the energy security is much worse - having transmission lines passing through a bunch of other countries - some of which are politically unstable. Also sub-sea interconnectors take years to provision - you might be looking at a decade long project while siting the panels locally means a year or couple of years project at most.
  - xvilka 5y ago
    Matter of the capacity though. You could cover half of the Sahara with panels. You can't cover half of the Europe with panels.
    - Nasrudith 5y ago
      We aren't nearly at that level of saturation, which makes doing so a bit premature, especially when prices are more likely to drop over time.
  - jdeibele 5y ago
    As a lay-person, I wondered about using solar power in Africa and then shipping ammonia to Europe (or wherever). https://www.ammoniaenergy.org/articles/round-trip-efficiency-of-ammonia-as-a-renewable-energy-transportation-media/ https://www.ammoniaenergy.org/articles/round-trip-efficiency... says that using fuel cells as transport yields only about 19% efficiency ... but that's comparable to 20% efficiency for fossil fuels. It's much better for stationary projects, up to twice as much. But as you say, it seems much better to build much more solar power capacity locally. If the local utility makes ammonia (or some other form of storage) to store for the winter, that seems to make more economic sense.
algo_trader 5y ago
Singapore for example, is a small dense industrialized island, and they dont have any good alternatives. You end up importing power over 2000km from the cheapest solar resource in the world (~20% power loss panel-to-home), or maybe import green ammonia to burn in generators (same panels, installed in Australia, ~70% efficiency loss). Of course both alternatives are more expensive than cheap coal. And if you are are a grumpy old man, go ahead and vote to delay and defer and deceive.

I’d love to see some hard numbers on the “sun cable”. At a high level it seems like the biggest pie in the sky bullshit.

by dav43 5y ago

I’d love to see some hard numbers on the “sun cable”. At a high level it seems like the biggest pie in the sky bullshit.

rswail 5y ago

Well, they've got serious investors and serious money at stake. Why is the concept of long distance HVDC cables, large energy storage and reusing flat, sunny land to generate power seem to be "pie in the sky"?

derriz 5y ago
There were a bunch of projects like this (Xlinks in the UK, a big German one and a few others) based around the idea of generating solar electricity in northern Africa and selling into Europe via HVDC cables under the Mediterranean. What has killed these projects (although Xlinks are seemingly still releasing press releases on a regular basis) is the radical shift in the relative prices of the components. Laying HDVC cables under the sea was and remains expensive while the price of solar PV panels has dropped by nearly 90% in a decade. As a result, the economics don't really add up any more. The capacity factor for a typical solar PV panel in northern Africa is about double that of one sited in northern Europe. But this increased efficiency cannot be exploited. It's now significantly cheaper to simply install twice as many PV panels in the north of Germany than install half the number of panels in the Sahara AND build 1000km of transmission to get the electricity to the markets in northern Europe. There are other disadvantages also; the energy security is much worse - having transmission lines passing through a bunch of other countries - some of which are politically unstable. Also sub-sea interconnectors take years to provision - you might be looking at a decade long project while siting the panels locally means a year or couple of years project at most.
- xvilka 5y ago
  Matter of the capacity though. You could cover half of the Sahara with panels. You can't cover half of the Europe with panels.
  - Nasrudith 5y ago
    We aren't nearly at that level of saturation, which makes doing so a bit premature, especially when prices are more likely to drop over time.
- jdeibele 5y ago
  As a lay-person, I wondered about using solar power in Africa and then shipping ammonia to Europe (or wherever). https://www.ammoniaenergy.org/articles/round-trip-efficiency-of-ammonia-as-a-renewable-energy-transportation-media/ https://www.ammoniaenergy.org/articles/round-trip-efficiency... says that using fuel cells as transport yields only about 19% efficiency ... but that's comparable to 20% efficiency for fossil fuels. It's much better for stationary projects, up to twice as much. But as you say, it seems much better to build much more solar power capacity locally. If the local utility makes ammonia (or some other form of storage) to store for the winter, that seems to make more economic sense.

algo_trader 5y ago

Singapore for example, is a small dense industrialized island, and they dont have any good alternatives. You end up importing power over 2000km from the cheapest solar resource in the world (~20% power loss panel-to-home), or maybe import green ammonia to burn in generators (same panels, installed in Australia, ~70% efficiency loss). Of course both alternatives are more expensive than cheap coal. And if you are are a grumpy old man, go ahead and vote to delay and defer and deceive.